The present invention relates to an arrangement for the electrical connection of a lamp.
The present invention relates more particularly to an arrangement for the electrical connection of a lamp, especially in a motor-vehicle headlamp, of the type in which the lamp includes a light-source element, axially at the front, and, at the rear, a lamp base equipped with fixed connecting terminals, of the type in which the lamp is fitted in a support by way of a hole and it is connected electrically to an electrical power-supply harness by having the fixed terminals put in contact with associated connecting terminals carried by a terminal block.
In general, the elements for fitting and connecting a motor-vehicle headlamp are arranged in the following way.
Electrical wires originating from the power-supply harness of the vehicle arrive in proximity to the rear face of the headlamp and are connected to the connecting sockets of a lamp holder.
The lamp includes contact strips oriented axially towards the rear.
The contact strips are inserted axially into the sockets associated with the lamp holder, then the lamp holder is fitted into a complementary receptacle arranged at the rear of the headlamp.
One of the main reasons explaining the difficulties encountered in forming the electrical connection in this type of arrangement is that the connecting manoeuvre has to be carried out xe2x80x9cblindxe2x80x9d.
This is because the accessibility to the lamps which equip the headlamps is often poor, which makes it difficult to change these lamps, in particular the manual operations aimed at inserting or removing the lamp, and the manual operations aimed at carrying out the electrical connection, or the disconnection respectively, of the lamp.
Moreover, these operations have to be able to be carried out by the driver of the motor vehicle. Consequently, handling operations have to be simple and prevent errors in fitting and/or in connection, while ensuring the safety of the driver and the reliable operation of the lamp.
During the manufacture of the connecting elements of the headlamp, a significant length of the electrical wires is generally provided so as to facilitate handling of the lamp holder and of the lamp upon connection.
Consequently, when the lamp holder is fitted into its receptacle, it transpires that the electrical wires are poorly positioned within the headlamp. They may, for example, be trapped in the elements for fixing the lamp onto its support or be jammed between the lamp and the reflector of the headlamp. These situations may be sources of malfunctioning of the headlamp.
In order to solve these problems, it is known, for example, to use a lamp holder with internal connections such as those which are described in the documents DE-A-298.23.160 and EP-A-0.898.114.
This type of arrangement is used especially in direction-change indicator lamps and in headlamps with an adjustable reflector.
In this type of arrangement, electrical wires for connecting to the power-supply harness of the vehicle are arranged in the framework of the headlamp and are connected to connecting terminals arranged in a receptacle carried by the rear face of the reflector.
The axial contact strips of the lamp are inserted into the corresponding sockets of a suitable lamp holder which includes connecting terminals complementary to those carried by the receptacle.
The lamp holder equipped with the lamp is fitted into the receptacle by a forwards axial movement, then a movement of pivoting of the lamp about its axis until the terminals of the lamp holder come into electrical contact with the associated terminals of the receptacle and form the connection.
These devices are not completely satisfactory. This is because problems of reliability may become apparent in use, which are due especially to their complex structure.
The operations necessary for the connection of a lamp according to this arrangement exhibit risks of errors which can lead to an incorrect connection of the lamp or to the deterioration of the elements constituting the arrangement.
Moreover, the substantial cost of these devices is a penalty.
The invention aims to remedy these drawbacks by proposing an economical arrangement which makes it possible to form the electrical connection of a lamp via simple handling operations.
To that end, the invention proposes an arrangement of the type described above, characterised in that the fixed terminals extend laterally overall from a portion of the axial surface of the lamp base outwards along directions which are each contained in a substantially transverse plane, and in that the terminal block is fitted movable with respect to the support between a locked position in which the connecting terminals are in electrical contact with the associated fixed terminals, and an unlocked position in which the connecting terminals are spaced away from the fixed terminals, in such a way that the movement of the terminal block to its locked position, or to its unlocked position, causes the connection, or the disconnection respectively, of the lamp with the electrical power-supply harness.
In a preferred way, the support consists of the reflector of the headlamp (the terminal block then being fitted movable with respect to the rear wall of the said reflector). However, this support can also be a piece other than the reflector, especially an additional piece advantageously fixed by any mechanical means to the rear wall of the reflector.
According to other characteristics:
the terminal block is fitted movable, with respect to the support, in a substantially transverse connecting plane;
the fixed terminals are substantially parallel to the transverse connecting direction, and the terminal block is fitted so as to slide along the transverse connecting direction;
the terminal block is fitted sliding on a slideway which is affixed to the support of the lamp;
the terminal block is fitted so as to pivot about an axis substantially parallel to the axis of the lamp;
the terminal block includes an arm which extends generally in the transverse connecting plane and which is fitted so as to pivot about its axis by one of its free extremities, so that the connection, or the disconnection, of the lamp takes place via pivoting of the terminal block towards the lamp, or spacing away from the lamp, respectively;
the axis of pivoting of the terminal block is substantially coaxial with the axis of the lamp;
the terminal block, in its axial face opposite the lamp, includes an axial clearance aperture which is associated with each fixed terminal of the lamp and which is offset in angle with respect to the corresponding connecting terminal in such a way that, in the unlocked position, each clearance aperture is substantially aligned radially with the associated fixed terminal, so as to allow withdrawal of the lamp axially rearwards;
the terminal block pivots about the axis of the lamp, sliding along a circumferential direction, and the terminal block includes at least one guide slot of overall circumferential orientation which interacts with at least two axial guide studs fixed into the support and passing through the associated slot, with a view to guiding the terminal block in sliding along the circumferential direction;
the terminal block is fitted pivoting about a substantially transverse axis and, in the locked position, each connecting terminal is in contact with a rear face of the associated fixed terminal, in such a way that, in order to pass from its locked position to its unlocked position, the terminal block pivots rearwards, and, in order to pass from its unlocked position to its locked position, the terminal block pivots forwards;
the fixed terminals are oriented along directions which are each substantially radial with respect to the axis of the lamp;
the lamp is fitted so as to pivot about its axis in the corresponding hole of the support, and the terminal block is designed to be placed in locked position after the fitting of the lamp in such a way that, in its locked position, it immobilises the lamp in its fitted position, and/or in such a way that, if it occupies its locked position before the fitting of the lamp, it then renders this fitting impossible;
the arrangement includes means for indexing the terminal block in its unlocked position;
the arrangement includes at least one abutment element which limits the displacement of the terminal block in the direction of its locking and/or of its unlocking;
the fixed terminals are contact strips substantially parallel to the transverse plane;
the terminal block includes a gripping element which makes it possible for a user to shift the terminal block from its locked position into its unlocked position, and conversely.